A wristwatch marketed by the Jaeger Lecoultre Company under the reference “Master Grand Reveil”, includes an alarm mechanism for automatically setting off an alarm at a time predefined by the user. This alarm function is performed by a mechanism connected to the movement, which includes an independent barrel, a setting system for programming the alarm time, a release mechanism that is connected to the gear train of the movement and actuates the alarm at the appointed time, and a strike work for alerting the user. The strike work includes both a gong which is struck by a hammer to generate an acoustic signal and means for vibrating the watch without generating an audible acoustic signal. There is a switch for selecting whether to release an acoustic alarm or a silent vibrating alarm.
This watch has, however, drawbacks. Indeed, the alarm mechanism requires an additional power source and includes elements that are specifically for the silent alarm operating mode of the mechanism, which increases the complexity and size of the structure. Moreover, the vibration amplitude is limited.